The Collaborative International Dictionary of English v.0.48:

Streamline \Stream"line`\, a.
   Of or pert. to a stream line; designating a motion or flow
   that is free from turbulence, like that of a particle in a
   streamline; hence, designating a surface, body, etc., that is
   designed so as to afford an unbroken flow of a fluid about
   it, esp. when the resistance to flow is the least possible;
   as, a streamline body for an automobile or airship; -- the
   current usuage prefers the term streamlined.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

streamlined
    adj 1: made efficient by stripping off nonessentials; "short
           streamlined meetings"; "a streamlined hiring process"
    2: designed or arranged to offer the least resistant to fluid
       flow; "a streamlined convertible" [syn: streamlined,
       aerodynamic, flowing, sleek]